CN113802474B

CN113802474B - Bridge half-width pass-protection construction method and half-width bridge beam slab stabilizing device

Info

Publication number: CN113802474B
Application number: CN202111012258.XA
Authority: CN
Inventors: 张立兵; 吴昊聪; 张洪铭; 欧阳禄龙; 唐智昶; 窦照金
Original assignee: China Construction Civil Engineering Co Ltd
Current assignee: China Construction Civil Engineering Co Ltd
Priority date: 2021-08-31
Filing date: 2021-08-31
Publication date: 2023-05-09
Anticipated expiration: 2041-08-31
Also published as: CN113802474A

Abstract

The invention relates to the technical field of bridge repairing construction, and provides a bridge half-width guarantor construction method for half-width guarantor construction operation of a bridge, which aims at bridge surface of which a plurality of beam plates are transversely spliced. Firstly, dismantling one side lane of an old bridge and marking the dismantled lane as a dismantling half width, and keeping the other side lane of the old bridge motionless and marking the lane as a keep-alive half width; then inward extrusion stress is applied from the left side and the right side of the keep-alive half-width bridge deck; then constructing half of the new bridge in the original position of dismantling the half, and canceling the extrusion stress on the bridge deck of the half bridge after the half bridge of the new bridge is in traffic; and finally, dismantling the full-bridge half width of the old bridge, and building the other half width of the new bridge in the original place. The invention also provides a half-width bridge beam slab stabilizing device matched with the applied extrusion stress. The scheme of the invention can maintain the traffic capacity of the road in the whole bridge construction process. And the dangerous situation caused by unstable passing-through part of the old bridge is avoided.

Description

Bridge half-width pass-protection construction method and half-width bridge beam slab stabilizing device

Technical Field

The invention relates to the technical field of bridge repairing construction, in particular to a construction method for performing half-width protection on old bridges and a matched stabilizing device for half-width bridge beam plates.

Background

The repairing flip cover for the bridge on the original road is different from the bridge construction on the brand new road, and the original bridge is maintained to have certain traffic capacity in the repairing period in many times. In this case, the vehicle is usually guided by first dismantling one of the lanes, i.e. one half of the lane, and then keeping the vehicle-guiding capability of the other half of the lane, so that the original vehicle can enter the reserved half of the lane for guiding.

However, many old bridges needing to be repaired are different from the existing integrated box girder bridges, and a plurality of girder plates are adopted to be spliced in the transverse direction, namely the left-right direction, to form a bridge deck. The half bridge deck is dismantled, vehicles are concentrated on the other half bridge deck, the vehicles are kept smooth, namely, the traffic is ensured, the traffic flow becomes large, the bridge beam plate of the bridge is easy to generate larger bending moment, or the wet joint of the bridge plate is stressed to crack under the condition that the vehicles start sudden braking to apply larger reaction force to the bridge deck, and even the whole bridge plate is translated. The safety of the half bridge in the construction period is difficult to ensure.

In the prior art, the general coping method is to directly fix the beam plates of the guarantor half-width bridge into a whole by utilizing the steel plates, and fix the steel plates by using expansion bolts, but the steel nails can damage the main body structure of the bridge, and the guarantor half-width normal traffic is easily influenced by irreversible damage to the guarantor half-width bridge. The device can only be installed on the bottom surface of the bridge, the installation and construction are very difficult, the personnel hoisting operation is required, and the device is not easy to dismantle in the later period.

Disclosure of Invention

The invention discloses a bridge half-width pass-through construction method.

The technical problems to be solved are as follows: some old bridges with a plurality of beam plates spliced into bridge decks from left to right are subjected to repairing construction, and when half-width bridge protection construction is performed by keeping certain traffic capacity, the half-width bridge plates are unstable, and the connecting joints between the beam plates are easy to crack and even the beam plates slide, so that the bridge safety is influenced.

In order to solve the technical problems, the half-width bridge protection construction method adopts the following scheme.

The bridge half-width guarantor construction method carries out half-width guarantor construction operation on a bridge with a bridge deck transversely spliced by a plurality of beam plates, and comprises the following steps:

step one: dismantling one side lane of the old bridge and marking as a dismantling half width, and keeping the other side lane of the old bridge motionless and marking as a keep-alive half width;

step two: applying inward extrusion stress from the left side and the right side of the keep-through half-width bridge deck;

step three: constructing a half-width lane of the new bridge in the half-width dismantling original position;

step four: after a half-width lane of the new bridge is used, removing extrusion stress applied to the keep-through half-width of the old bridge;

step five: and dismantling the full-bridge half width of the old bridge, and building the other half width lane of the new bridge in situ.

Preferably, in the second step, a beam plate stabilizing device is adopted to load extrusion stress, and a plurality of beam plate stabilizing devices are arranged at intervals in the length direction of the beam plate; the beam plate stabilizing device comprises two fixing clamps which can be respectively fixed on the left side and the right side of the bridge deck of the keep-alive half width, the two fixing clamps are connected through a tightening mechanism, the tightening mechanism is arranged below the beam plate, and the tightening mechanism tightens the two fixing clamps to apply inward extrusion stress to the keep-alive half width.

Preferably, in the second step, the bridge deck with the half width of the retaining at the fixing clip position is trimmed, so that the fixing clip and the bridge deck are stressed uniformly.

Preferably, in the first step, the bridge plate removing operation is sequentially performed from the side of the adjacent side of the half-width removing frame to the side of the protecting frame; before the beam plate dismantling operation, the asphalt pavement of the half bridge deck is dismantled for cutting and separating operation, and the cutting is carried out along the splicing seams between the beam plates.

Preferably, before the cutting and separating operation of the asphalt pavement in the first step, the asphalt pavement with two ends of the half-width removed is planed to expose the positions of the beam-slab splice seams; and scribing the beam slab splice joint positions on the asphalt pavement according to the side edges of the bridge deck and the exposed bridge splice joint positions, and then cutting and separating the asphalt pavement along the scribing lines.

Preferably, in the third step, a gap is reserved between the half-width of the new bridge and the half-width of the old bridge, and the gap range is not smaller than 10cm, and can be determined according to actual design conditions. So as to avoid direct contact between the new bridge and the guarantor half-width.

Preferably, in the fifth step, the bridge pier of the guarantor half width is dismantled from top to bottom.

The invention also provides a half-width bridge beam slab stabilizing device for reinforcing the beam slab of the half-width bridge, which adopts the following scheme.

The half-width bridge beam slab stabilizing device is used for applying extrusion stress inwards to the beam slabs of the bridge with half width when the bridge deck is subjected to half-width bridge protection construction operation by a plurality of bridges with the beam slabs transversely spliced,

the beam plate stabilizing device comprises two fixing clamps which can be fixed on the side edge of the bridge deck and are connected through a tightening mechanism,

the two fixing clamps are respectively arranged on the left side and the right side of the bridge keep-alive half-width, the tightening mechanism is positioned below the bridge, the two ends of the tightening mechanism are respectively connected with the fixing clamps on the two sides of the keep-alive half-width, and the tightening mechanism can stretch and shrink to adjust the distance between the two fixing clamps so as to apply inward extrusion stress to the bridge deck of the keep-alive half-width.

Preferably, the fixing card is U-shaped, is matched with the left side edge and the right side edge of the bridge passage half width, and has anti-slip textures at the inner edge; one side of the fixing clip on one side of the limb is clamped in the water flowing hole of the bridge deck, or the bridge guardrail is grooved, one side of the fixing clip is clamped in the groove, and the guardrail is arranged on the fixing clip on the other side.

Preferably, the tightening mechanism is a steel wire rope with a rope tightener, the rope tightener is arranged on one side of the bridge facing edge, two ends of the steel wire rope are fixed on a fixing clamp on one side of the bridge facing edge, a pulley is arranged on the lower portion of the fixing clamp on the other side, and the steel wire rope bypasses the pulley.

Compared with the prior art, the bridge half-width pass-through construction method has the following beneficial effects:

the bridge with the bridge deck formed by transversely splicing the plurality of beam plates from left to right is provided with blocking structures at the left side and the right side of the supporting structure, the outermost beam plates are prevented from moving outwards, and then the beam plates in the middle of the whole bridge deck are restrained by the beam plates at the two sides to keep the positions of all the beam plates of the whole bridge deck fixed. The half-width bridge can be dismantled by half-width protection construction, and the beam plates exposed at the outermost sides at the moment lose the restraint of the original beam plates, so that the bridge is inevitably moved under the condition of high stress.

In the invention, after the half bridge is dismantled, inward pressurizing stress is applied to the bridge deck of the half bridge from the left side and the right side, so that the exposed beam plates after the half bridge is dismantled can be surrounded by the extruding acting force, and the beam plates are prevented from moving.

For the whole construction, a half bridge is firstly dismantled, the rest bridge is reserved and is generally used as a traffic-keeping half width, the traffic-keeping half width is reinforced in a mode of applying extrusion stress, and meanwhile vehicles are guided to the traffic-keeping half width, so that certain traffic capacity of a road is maintained. And then, in order to align with the roads at the two ends, constructing half of the new bridge at the original position, waiting until the half of the new bridge can be passed after the construction is completed, and guiding the vehicle to the half of the bridge on which the new bridge is constructed. The applied force on the guarantor's half-width is then removed and the guarantor's half-width of the old bridge is removed. And constructing the other half of the new bridge. Thus, the basic traffic capacity of the original road is always maintained in the whole bridge construction process. The road is prevented from being directly blocked to influence traffic.

Meanwhile, the invention also provides a half-width bridge beam plate stabilizing device, which changes the original installation mode that the steel plate is fixed on the beam plate through expansion bolts after crossing the beam plate joint. The tightening mechanism is connected with the two fixing clamps which can be clamped at two sides of the bridge deck, the two fixing clamps are connected to two sides of the full-width half maximum, and then the tightening device tightens the two fixing clamps to gather all the beam plates into a whole. The beam plate exposed at the outermost side is prevented from translating under the action of external forces such as braking and the like. At the same time, in order to avoid that the tightening device affects the vehicle on the deck, the tightening device is thus arranged below the deck. Because the tightening device is not connected with the bridge deck, the tightening device is only lifted to the lower surface position of the bridge deck from the left side and the right side of the bridge by using ropes and then is connected with the fixing clips. Or directly lifting the whole beam plate fixing device from the lower part of the bridge, and then installing the fixing clip on the side edge of the retaining half-width, and tensioning the tightening device.

This scheme sets up simply, easy dismounting has avoided the influence that the operation of punching caused the structure of bridge on the bridge board, has also avoided the inconvenient problem of operation at bridge lower surface simultaneously.

Drawings

FIG. 1 is a cross-sectional view of a half bridge deck stabilization device of the present invention after installation;

FIG. 2 is a schematic view of the fastener and tensioner portion of the critical side of FIG. 1;

FIG. 3 is an enlarged view at A in FIG. 2;

fig. 4 is a schematic view of the other side fixing clip of fig. 1.

Reference numerals illustrate: 1-beam plate, 2-fixing clip, 3-tightening mechanism, 3 a-steel wire rope and 3 b-rope tightener.

Detailed Description

The following describes specific embodiments of the present invention in detail with reference to the drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the invention, are not intended to limit the invention.

In the present invention, unless otherwise indicated, terms of orientation such as "up, down, left, right" are used to refer generally to up, down, left, right as shown with reference to fig. 1; "inner and outer" means inner and outer relative to the contour of the respective parts themselves. The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

In order to solve the problems that when old bridges with a plurality of beam plates 1 spliced into bridge decks from left to right are subjected to repairing construction and half-width bridge beam plates 1 are unstable when certain traffic capacity is maintained to perform half-width traffic protection construction, connecting joints among the beam plates 1 are easy to crack and even the beam plates 1 slide, and the safety of the bridges is affected.

The invention provides a bridge half-width guarantor construction method which is specially used for half-width guarantor construction operation of a bridge of which a bridge deck is transversely spliced by a plurality of beam plates 1, and comprises the following steps:

step three: constructing half of the new bridge in the original position of the half of the bridge,

step four: after a half-width lane of a new bridge is used for driving, the extrusion stress on the bridge deck with the half-width is removed;

step five: and dismantling the full-bridge half width of the old bridge and building the other half width of the new bridge in the original place.

The dismantling half-width and the passing-through half-width are only definitions for convenience of description, and do not represent that in actual construction, one side of a bridge is necessarily the dismantling half-width or the passing-through half-width, and it can be determined which side is dismantled first according to actual conditions to reserve. Then the first side of demolishing is demolishing half-width, and the other side is the guarantor half-width. After the half-width is dismantled, all pedestrians and vehicles passing through the bridge are guided to the pass-keeping half-width, so that the basic traffic capacity of the bridge is maintained.

Immediately after the half-width beam panel 1 is removed, compressive stress is applied to both sides of the remaining half-width. The extrusion stress can apply acting force to the direction of the half-width of the reserved half-width by adopting a jack or a wedge block and the like on the side surface of the beam slab 1 exposed after the half-width beam slab 1 is dismantled, and then the original blocking structure at the side edge of the bridge applies reaction force to fulfill the aim of applying the extrusion stress inwards from two sides. However, in many cases, the condition for mounting the jack is not provided on the side of the half-width removal. The two sides of the hold-down half-width are clamped simultaneously by the same device, which is then pressed inwards, as well as the compression stress on the hold-down half-width.

Then, in step three, in order that the new bridge can be reconnected with the original road, half of the new bridge is built in the site of dismantling half. The new bridge design should employ two half-frames separately supported structures.

And step four, after the half width of the new bridge is connected with the road and is in traffic, transferring the traffic function of the old bridge, which is originally in the traffic-keeping half width of the old bridge, to the half width of the new bridge which is already in traffic. And then dismantling the guarantor half width of the old bridge, and then carrying out construction of the other half width of the new bridge on the original site of the dismantled guarantor half width.

Specifically, in the second step, loading extrusion stress by adopting a beam plate stabilizing device, and arranging a plurality of beam plate stabilizing devices at intervals in the length direction of the beam plate 1;

the beam plate stabilizing device comprises two fixing clamps 2 which can be respectively fixed on the left side and the right side of the bridge deck with a half width, the two fixing clamps 2 are connected through a tightening mechanism 3, the tightening mechanism 3 is arranged below the beam plate 1, and the tightening mechanism 3 tightens the two fixing clamps 2 to apply inward extrusion stress to the half width. The tightening device may be a wire rope 3a and a tensioning mechanism of the wire rope 3a in the drawings, or may be a double-ended screw or the like as long as it can be extended and contracted.

Preferably, the bridge deck of the half width of the guarantor at the position of the fixing clamp 2 is trimmed, so that the stress of the fixing clamp 2 and the bridge deck is uniform. The fixing clip 2 is determined according to the specific situation of the installation position of the bridge, and needs to be matched with the bridge deck. However, concrete residues exist on wet joints of the asphalt pavement or the beam slab 1 on the bridge deck, so that the installation and stress of the fixing clamp 2 and the bridge deck are affected.

Step one, the bridge dismantling operation of the beam slab 1 is sequentially carried out from the side of the side edge of the dismantling half width to the side of the guarantor; before the beam plate 1 is dismantled, the asphalt pavement of the half bridge deck is dismantled for cutting and separating operation, and the cutting is carried out along the splicing seams between the beam plates 1. Because the left half-width bridge and the right half-width bridge of the lanes on the two sides of the old bridge are connected into a whole, the asphalt pavement is also bonded into a whole. The asphalt pavement is cut from the middle in order to avoid affecting the asphalt pavement on the keep-through half-width. Meanwhile, in order to facilitate the dismantling of the beam plates 1, the asphalt pavement is cut along the splicing seams of the beam plates 1, so that the beam plates 1 are thoroughly separated. Specifically, before the cutting and separating operation in the first step, planing the asphalt pavement at the two ends of the demolishing half-width to expose the positions of the splice seams of the beam plates 1; and scribing the joint seam position of the beam slab 1 on the asphalt pavement according to the side edges of the bridge deck and the exposed joint seam position of the bridge, and then cutting and separating the asphalt pavement along the scribing.

In the third step, gaps are reserved between the half-width of the new bridge and the half-width of the old bridge to avoid direct contact between the new bridge and the half-width of the old bridge. Thus, interference collision between the half-width of the bridge and the half-width of the new bridge is avoided, the structural safety of the half-width of the bridge is influenced, and meanwhile, the influence on the half-width of the new bridge is avoided. In the fifth step, the other half of the new bridge is preferably kept with a gap from the half constructed in the third step in advance, and a separated bridge structure is adopted.

And fifthly, removing the bridge pier which is ensured to be half-width from top to bottom, and avoiding the bridge pier from overturning.

The bridge pier of the old bridge is generally in three forms:

1. an independent bridge pier supports two half-width bridge decks at the same time. In this time, the bridge pier of the old bridge is required to be reserved, and only the bridge slab 1 which is repeatedly removed is removed, so that the bridge pier is continuously supported and kept open for half a width. Preferably, after the half beam plate 1 is removed, half upper surface of the bridge pier is exposed, and one end of the exposed upper surface of the bridge pier near the half beam plate is removed downwards, so that interference with construction of the beam plate 1 bent cap and other parts of the new bridge is avoided.

2. The two independent piers respectively support the left half beam plate 1 and the right half beam plate 1, so that the situation is easier to process, and only the half support piers are required to be dismantled directly, and then the construction of a new bridge is carried out. And then the bridge pier of half width is kept from being processed.

3. The three piers support the left and right half-width beam plates 1 of the left and right bridges. This is rare, but the treatment method combines the first two types, removes the bridge pier at the outermost side of the half-width, reserves the bridge pier at the middle and supports the left and right half-width, reserves the bridge pier in the middle and keeps the bridge pier at the half-width, and removes the beam slab 1 at the half-width, and removes the exposed part of the bridge pier in the middle downwards for a certain distance.

The invention provides a half-width bridge beam slab stabilizing device, which is matched with the step two, and applies inward extrusion stress to a bridge deck keep-through half-width.

When the bridge is used for half-width bridge protection construction operation of which the bridge deck is transversely spliced by a plurality of beam plates 1, extrusion stress is applied inwards to the beam plates 1 of the bridge with half-width, the beam plate stabilizing device comprises two fixing clamps 2 which can be fixed on the side edge of the bridge deck, the two fixing clamps 2 are connected through a tightening mechanism 3,

two fixing clips 2 are respectively arranged on the left side and the right side of the bridge keep-alive half width, a tightening mechanism 3 is arranged below the bridge, two ends of the tightening mechanism are respectively connected with the fixing clips 2 on the two sides of the keep-alive half width, and the tightening mechanism 3 can stretch and shrink to adjust the distance between the two fixing clips 2 so as to apply inward extrusion stress to the bridge deck of the keep-alive half width.

Meanwhile, the invention also provides a half-width bridge beam plate stabilizing device, which changes the original installation mode that the steel plate is fixed on the beam plate 1 through expansion bolts after crossing the joint of the beam plate 1. The tightening mechanism 3 is adopted to connect two fixing clamps 2 which can be clamped at two sides of the bridge deck, the two fixing clamps 2 are only required to be connected to two sides of the full-width half maximum, and then the tightening device is used for tightening the two fixing clamps 2, so that all the beam plates 1 can be gathered together. The beam plate 1 exposed at the outermost side is prevented from translating under the action of external forces such as braking and the like. At the same time, in order to avoid that the tightening device affects the vehicle on the deck, the tightening device is thus arranged below the deck. The tightening device is not connected with the bridge deck, so that the tightening device is lifted to the lower surface position of the bridge plate 1 from the left side and the right side of the bridge by ropes and then is connected with the fixing clip 2. Or directly lifting the whole beam plate 1 fixing device from the lower part of the bridge, and then installing the fixing clip 2 on the side edge of the retaining half-width, and tensioning the tightening device.

Specifically, the fixing clip 2 can be clipped on the side edge of the bridge deck or the beam slab 1, and then when an inward external force is applied to the fixing, the fixing clip 2 can conduct the external force to the beam slab 1 of the bridge, and the concrete expression form is not restricted. The external force of the fixing clips 2 is applied through the tightening mechanism 3, and the tightening mechanism 3 simultaneously applies acting force towards the inner side of the bridge to the two fixing clips 2 during the contraction movement. The tightening mechanism 3 is a mechanism capable of contracting and expanding while applying a pulling force during contraction and maintaining the pulling force. It may be a screw or a hydraulic mechanism, but the screw or the hydraulic mechanism is heavy and costly and is not an application of the present invention. Therefore, the wire rope 3a with the rope tightener 3b is preferably adopted in the invention, the rope tightener 3b can enable the wire rope 3a to shrink or stretch, the wire rope 3a directly applies tension to the two fixing clamps 2, the rope tightener 3b can be directly arranged on the wire rope 3a and can be a hand-operated wire winding device as shown in fig. 2, then a ratchet wheel is used for fixing and keeping tension, and the rope tightener can also be any wire rope 3a tightener 3b, and only the wire rope 3a can be tightened and fixed. Preferably, for operation convenience, the rope tightener 3b is disposed on one side of the bridge facing edge, and further preferably, two ends of the steel wire rope 3a are fixed on the fixing clip 2 on one side of the bridge facing edge, and a pulley is mounted on the lower portion of the fixing clip 2 on the other side, and the steel wire rope 3a bypasses the pulley. Alternatively, as shown in fig. 2, one or more wires may be used to directly connect two fixing clips 2 to each end of the wire rope 3 a. The rope tightener 3b may be fixed to the fixing clip 2 according to the type of the rope tightener 3b, and then one end of the wire rope 3a is connected to the rope tightener 3b, and the other end is connected to the other fixing clip 2.

The fixing card 2 is U-shaped and is matched with the left side edge and the right side edge of the bridge passage half width, and the inner edge of the fixing card 2 is provided with anti-skid textures; the anti-slip texture prevents the fixing clip 2 from falling off. One side of the fixing clip 2 on the side facing to the side is clamped in the water flowing hole of the bridge deck, or one side of the fixing clip 2 is clamped in the slot on the bridge guardrail, or the fixing clip 2 on the side facing to the side can be directly fixed on the guardrail under the condition that the guardrail of the bridge is firm as shown in fig. 2. The other side is simpler, and as shown in fig. 3, the other side is directly clamped on the exposed beam plate 1.

As shown in fig. 2, the fixing clip 2 is provided with a mounting seat, and the mounting seat serves as a mounting base of the guardrail. The guardrail provides safety assurance for the bridge exposure side simultaneously.

Because the steel wire rope 3a is inevitably bent on the beam plate 1, a pad plate is arranged at the broken line of the beam plate 1 on the steel wire rope 3a for dispersing the pressure of the steel wire rope on the beam plate.

The fixing clamp 2 is U-shaped and comprises an upper plate, a lower plate and a side plate, wherein the upper end and the lower end of the side plate are respectively connected with the side edges of the upper plate and the lower plate; the fixing card 2 is made of metal.

The above examples are only illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solution of the present invention should fall within the scope of protection defined by the claims of the present invention without departing from the spirit of the design of the present invention.

Claims

1. The bridge half-width guarantor construction method aims at bridge construction operation of bridge with bridge deck transversely spliced by a plurality of beam plates (1), and comprises the following steps:

step five: dismantling the remaining half width of the old bridge and building the other half width lane of the new bridge in situ;

loading extrusion stress by adopting a beam plate stabilizing device in the second step, and arranging a plurality of beam plate stabilizing devices at intervals in the length direction of the beam plate (1); the beam plate stabilizing device comprises two fixing clamps (2) which can be respectively fixed on the left side and the right side of a bridge floor with a half width, the two fixing clamps (2) are connected through a tightening mechanism (3), the tightening mechanism (3) is arranged below the beam plate (1), and the tightening mechanism (3) tightens the two fixing clamps (2) to apply inward extrusion stress to the half width.

2. The bridge half-width bridge girder-retaining construction method according to claim 1, wherein in the second step, the bridge deck of the girder-retaining half-width at the position of the fixing clip (2) is trimmed so that the stress of the fixing clip (2) and the bridge deck is uniform.

3. The bridge half-width guarantor construction method according to claim 1, characterized in that in step one, the dismantling operation of the bridge beam plate (1) is performed from the side of the side edge of the dismantling half-width to the guarantor side in sequence;

before the dismantling operation of the beam plates (1), the asphalt pavement of the half bridge deck is dismantled for cutting and separating operation, and the cutting is carried out along the splicing seams between the beam plates (1).

4. The bridge half-width pass-protection construction method according to claim 3, wherein before the cutting and separating operation of the asphalt pavement in the first step, the asphalt pavement at the two ends of the half-width is removed and the positions of the splice seams of the beam plates (1) are exposed; and scribing the splicing seam position of the beam slab (1) on the asphalt pavement according to the side edges of the bridge deck and the exposed splicing seam position of the bridge, and then cutting and separating the asphalt pavement along the scribing.

5. The bridge half-width bridge traffic-preserving construction method according to claim 1, wherein in the third step, a gap is left between the traffic-preserving half-width of the new bridge and the traffic-preserving half-width of the old bridge so as to avoid direct contact between the new bridge and the traffic-preserving half-width.

6. The bridge half-width bridge girder construction method according to claim 1, wherein in the fifth step, bridge piers of the girder are dismantled from top to bottom.